1. Field of the Invention
The present invention generally relates to a printer with a print head which can be pressed by the force of a spring against a counterpressure roller to print on a material disposed between the counterpressure roller and the print head. Such a print head can also be liftable away from the counterpressure roller. In such a printer, the active strand of a printing ribbon and a medium to be printed preferably run between the print head and the counterpressure roller, and there can preferably be a device to neutralize the application pressure between the print head and the counterpressure roller when the printing ribbon is stationary.
2. Background Information
One such type of printer is disclosed in German Patent No. DE 41 08 172 A1. With such a printer, for example, if labels on a backing medium are to be printed, or if only portions of the medium to be printed are to be printed as labels, there will typically be intermediate areas between two labels, or, in other words, areas which are not printed. To conserve the thermal transfer ink ribbon, therefore, a device is used so that during "economy" operation--during which the medium to be printed is not printed but continues to move past the print head--the thermal print head remains in the printing position and the counterpressure roller is moved into a position away from the print head. The transport of the transfer ribbon is thereby interrupted.
But on such a known printer, it is possible that if there is insufficient distance between the print head and the counterpressure roller, which can occur for a short time, for example, while the counterpressure roller is in motion, the thermal transfer ribbon can be unintentionally advanced if the ribbon comes into contact with the medium being printed, which also continues to advance.